1. Field of the Invention
This invention relates to a method for an automatic machine-plate change in a rotary printing press and an apparatus for the same and, more particularly, to automatization of a work, including delivery of a machine-plate, which the machine-plate wound around a plate cylinder of the rotary printing press is changed for a new machine-plate.
2. Description of the Related Art
Generally, in a rotary printing press, priming is facilitated to ink in a sheet-shaped machine-plate wound around a circumferential surface, and then transferred onto paper or the like with ink on the machine-plate which is rotated.
Conventionally, various automatization has attempted changing the machine-plates of a used-plate and a new-plate.
The typical instance is an automatic machine-plate change method which uses a robot and a vacuum device. In this method, the machine-plate change is performed to deliver the machine-plate onto the plate cylinder or from the plate cylinder by moving the machine-plate by means of the robot while a vacuum pat of the vacuum device is sucking the machine-plate.
The work of changing the machine-plates includes the aforementioned delivering work of the machine-plates (the work of delivering a new-plate onto the plate cylinder and the work of delivering a used-plate from the plate cylinder), and moreover, the work of winding the new-plate onto the plate cylinder and removing the used-plate wound around the plate cylinder thus far. Ordinarily, for winding of the machine-plate onto the circumferential surface of the plate cylinder, a plate catch system, involvedly engaging the end of the machine-plate into a catch shaft rotatably placed in the plate cylinder, is used. The catch shaft of the plate catch system has a slit, extending in the axis direction, to catch the end of the machine-plate at the slit.
In regards to the automatization of the work of winding and removing the machine-plate, there is a plate change system disclosed by the present applicant (Japanese Patent Application Laid-open No. Hei. 5-246013). The plate change system includes a catch shaft driving means causing the catch shaft to rotate with an air cylinder device or the like, a weight roller pressing the machine-plate onto the plate cylinder by being rotatably moved to attach the circumferential surface of the plate cylinder, and a roller driving means performing the attachment and release of the roller by rotatably moving the roller with the air cylinder device or the like, thereby the automatization of the work of winding and removing the machine-plate is facilitated.
In the method for the automatic machine-plate change, in which it uses the aforementioned robot and vacuum device, there is a disadvantage caused by decreasing certainty and reliability because of the possibility of insufficient suction of the vacuum pat. That is, surroundings of each priming portion of the rotary printing press is in an undesirable state caused by, for example, ink-mist and paper-dust, which causes a sucking mouth of the vacuum pat to easily close, so that it is possible that the machine-plate slips off or is out of place because of the insufficient suction during delivery. It is possible that, the winding of the plate cylinder is difficult to be performed smoothly if the machine-plate slips off, if the machine-plate is out of place and falls and the machine-plate is damaged, whereby improvement of certainty and reliability has been expected.
Furthermore, there is a disadvantage in the cost for facilities which become very high when the expensive robot is provided in each upper and lower plate cylinder.
In order to reduce cost for facilities, there is a device used for delivering the machine-plates to both the upper and lower plate cylinders by using one robot to move both plates. But, in the above device, a wide space is required to move the robot, a high costing movement system of the robot is required, and work efficiency is decreased by taking much time to change the machine-plates because of the time involved in moving the robot, producing disadvantages.
Therefore, the automatization of the work of winding and removing the machine-plate in accordance with the present applicant, and further, the work of delivering the machine-plate is intended to be a much more efficient automatization.
It is an object of the present invention to provide the method for the automatic machine-plate change in the rotary printing press and the apparatus for the same, which increase certainty and reliability, in which the machine-plate change can be actualized by simple structure and operation and can be quickly and efficiently performed, and in which the cost for facilities can be reduced.